Methods And Devices For Tissue Retraction

ABSTRACT

Methods and devices are provided for retracting tissue. In one exemplary embodiment, a retractor is provided that includes a base, a plurality of blades extending from the base, and an actuator coupled to the base and operatively connected to the blades. The actuator can be configured to be actuated to move the blades relative to the base, thereby allowing the blades to retract tissue. The actuator can be self-locking so as to allow the blades to be freely movable within their entire range of motion relative to the base through actuation of the actuator without using another mechanism to lock the blades in a fixed position and to unlock the blades from the fixed position. The retractor can be formed from one or more radiolucent materials.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/435,355 filed on Mar. 30, 2012, which is hereby incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to methods and devices fortissue retraction, and in particular to bladed retractors and methodsfor use.

BACKGROUND OF THE INVENTION

In surgical procedures, it is preferable to minimize or reduce trauma tothe patient and damage to tissue. To achieve this result, surgeons tryto keep incisions as small as possible. However, it is usually necessarythat the surgeon have a clear view of the operating field.

A variety of retractors are available to keep an incision open andprovide a clear view of the operating field. Retractors are used insurgical operations to reposition muscular tissue, vessels, nerves, andother tissue with the aid of retractor blades, thereby providing accessto the site of the operation. Surgical retractors are particularlyimportant in performing surgical procedures that involve the spinalcolumn, where access to the surgical site can be obtained, for example,through a posterior, posterior-lateral, anterior, lateral, or ananterior-lateral approach.

Retraction can be performed in a variety of ways. In some embodiments, astep-wise dilation of the surgical incision can be performed togradually dilate the muscles and tissues to the required size to insertthe retractor. Step-wise dilation can involve the use of a series ofdilators or cannulae with successively larger diameters. This methodinvolves first inserting the smallest dilator or cannula into anincision. Then a second dilator or cannula, with a slightly largerdiameter, is slid over the smaller dilator or cannula and into theincision, thereby causing the incision to expand to the slightly largerdiameter of the second dilator or cannula. This process can be repeatedusing a series of dilators or cannulae with successively largerdiameters, until the incision is large enough to allow for insertion ofthe retractor. Once positioned, the retractors produce a small surgicalsite or window.

In some embodiments, a retractor can include multiple blades attached toa frame. The blades can be inserted into tissue and moved apart from oneanother to retract the tissue. However, moving the blades apart from oneanother can be cumbersome depending on where access to the surgical siteis obtained, e.g., awkward positioning of the surgeon relative to theretractor during lateral approach to a spine. It can also be difficultto adjust the blades to a particular desired position without moving theblades apart from one another too much, thereby causing problem(s) suchas harming nearby tissue or pushing against a nerve.

Accordingly, a need exists for improved methods and devices for tissueretraction.

SUMMARY OF THE INVENTION

In one embodiment, a surgical device is provided that includes a base, aplurality of retractor blades having a proximal end coupled to the baseand a distal portion extending distally from the base, and an actuatorcoupled to the base. The blades are configured to move radially relativeone another to move between a collapsed position and an expandedposition in which the blades define a working channel for receiving aninstrument therethrough and in which a diameter of the working channelis greater than the diameter of the working channel when the blades arein the collapsed position. The actuator is configured to rotate relativeto the base to cause the blades to move between the collapsed andexpanded positions. In an exemplary embodiment, the base, the blades,and the actuator can be formed from a radiolucent material.

The actuator can have a variety of configurations. For example, theactuator can be seated in the base and can be operatively connected tothe proximal ends of the blades. In one embodiment, the actuator can beself-locking such that the actuator is configured to freely move theblades between the collapsed and expanded positions without requiringactuation of a release mechanism. The actuator can be configured suchthat rotating the actuator in a first direction moves the blades to thecollapsed position, and rotating the actuator in a second directionopposite to the first direction moves the blades to the expandedposition. In an exemplary embodiment, the actuator can include a scrollgear, e.g., a self-locking scroll gear. In another exemplary embodiment,the actuator can be in the form of a ring disposed within a track formedin the base.

The blades can also have a variety of configurations. In one embodiment,when the blades are in the collapsed position at least one of the bladescan have an inner surface facing an outer surface of at least anotherone of the blades such that the at least one of the blades and the atleast another one of the blades overlap.

In another embodiment, a surgical device is provided that includes abase and a plurality of retractor blades extending from the base. Theplurality of retractor blades can have a collapsed position and anexpanded position. The plurality of retractor blades in the collapsedposition can overlap one another such that the plurality of retractorblades define a single working channel having a closed cylindricalshape. The plurality of retractor blades in the expanded position arespaced a distance apart from one another. In one embodiment, when theplurality of retractor blades are in the collapsed position, at leastone of the plurality of retractor blades is positioned radially inwardof at least another one of the plurality of retractor blades.

The surgical device can also include an actuator coupled to the base. Inone embodiment, the actuator can be configured to rotate relative to thebase to cause the plurality of retractor blades to move between thecollapsed and expanded positions. In an exemplary embodiment, theactuator can include a self-locking scroll gear.

In another embodiment, a surgical device is provided that includes abase, a plurality of retractor blades extending from the base andconfigured to retract tissue, and a self-locking actuator coupled to thebase. Each of the blades have a proximal end coupled to the base. Theblades are configured to move radially toward and away from one another.The actuator, e.g., a scroll gear, is configured to move relative to thebase to cause the blades to move radially toward and away from oneanother, and the actuator is configured to self-lock the blades in anyselected position relative to one another within a range of movement ofthe blades.

The actuator can vary in any number of ways. For example, the actuatorcan be configured to self-lock the blades in any selected positionrelative to one another by moving the actuator relative to the basewithout actuation of a lock mechanism, and the blades can be configuredto unlock by moving the actuator relative to the base without actuationof a release mechanism. In one embodiment, the actuator can beconfigured to rotate relative to the base to cause the blades to movetoward and away from one another.

In another aspect, a surgical method is provided that includes insertinga retractor through an incision formed in tissue, and rotating anactuator of the retractor in a first direction relative to a base of theretractor to cause blades of the retractor that are coupled to the baseto move radially away from one another to expand the incision and toform a working channel that provides access to a body cavity.

The method can have any number of variations. For example, the actuatorcan self-lock to lock the blades in a fixed position relative to oneanother. The actuator can be rotated relative to the base withoutactuating a release mechanism. For another example, the actuator can berotated in a second direction opposite to the first direction to causethe blades to move radially toward one another. For still anotherexample, one of the blades can be coupled to a fixed support of theretractor. The one of the blades can remain stationary when the actuatoris rotated in the first direction. For yet another example, afterexpanding the incision, an area including the incision can beradioimaged to produce a radiographic image. The base, the blades, andthe actuator can be radiolucent such that the base, the blades, and theactuator are invisible in the radiographic image.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is an x-ray image of one embodiment of a retractor formed from aradiolucent material retracting tissue adjacent to a spine;

FIG. 2 is an x-ray image of one embodiment of a retractor formed from anon-radiolucent material retracting tissue adjacent to a spine;

FIG. 3 is a perspective view of one embodiment of a retractor in aclosed position;

FIG. 4 is a side view of the retractor of FIG. 3;

FIG. 5 is another perspective view of the retractor of FIG. 3;

FIG. 6 is a cross-sectional view of the retractor of FIG. 5;

FIG. 7 is a perspective view of the retractor of FIG. 3 in an openposition with blades of the retractor partially expanded;

FIG. 8 is a cross-sectional view of the retractor of FIG. 7;

FIG. 9 is a perspective view of the retractor of FIG. 3 in an openposition with blades of the retractor fully expanded;

FIG. 10 is a cross-sectional view of the retractor of FIG. 9;

FIG. 11 is a perspective view of a base of the retractor of FIG. 3;

FIG. 12 is a side view of an actuator of the retractor of FIG. 3;

FIG. 13 is a perspective view of the actuator of FIG. 12;

FIG. 14 is a bottom view of the actuator of FIG. 12;

FIG. 15A is a perspective view of a blade of the retractor of FIG. 3;

FIG. 15B is a side view of the blade of FIG. 15A;

FIG. 16 is a bottom view of the retractor of FIG. 3 without the base ofthe retractor;

FIG. 17 is a bottom view of the retractor of FIG. 7 without the base ofthe retractor;

FIG. 18 is a perspective view of an obturator advanced to a spine;

FIG. 19 is a perspective view of the retractor of FIG. 3 being advancedover the obturator of FIG. 18; and

FIG. 20 is a perspective view of the retractor of FIG. 19 advanced tothe spine and having a surgical instrument inserted therethrough.

DETAILED DESCRIPTION OF THE INVENTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those of ordinary skill in the art will understand that thedevices and methods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the present invention is defined solely by the claims. Thefeatures illustrated or described in connection with one exemplaryembodiment may be combined with the features of other embodiments. Suchmodifications and variations are intended to be included within thescope of the present invention.

Various exemplary methods and devices are provided for tissueretraction. In general, the methods and devices can allow tissue to beretracted without the need to lock the retractor in place and/or withoutthe retractor leaving a radiographic footprint. In an exemplaryembodiment, a retractor is provided that includes a base, a plurality ofblades extending from the base, and an actuator coupled to the base andoperatively connected to the blades. The actuator can be configured tobe actuated to move the blades relative to the base, thereby allowingthe blades to retract tissue. The actuator can be self-locking so as toallow the blades to be freely movable within their entire range ofmovement relative to the base through actuation of the actuator withoutusing another mechanism to lock and unlock the blades relative to thebase. In other words, when the actuator is being actuated, e.g., movedrelative to the base, the actuator can cause the blades to move relativeto the base, and when the actuator is not being actuated, e.g., theactuator is not moving relative to the base, the blades can be locked ina fixed position relative to the base without the need for a separatelocking mechanism. A single actuator can therefore both move the bladesrelative to the base and lock the blades in a fixed position relativethereto, thereby simplifying use of the retractor. The actuator canallow for predictable control of blade position because once theactuator stops being actuated, the blades can be automatically locked inposition without a risk of the blades shifting position after the bladesand without a need for a locking mechanism.

The retractors disclosed herein can be formed from a variety ofmaterials. Non-limiting examples of materials that can form a retractorinclude metals, polymers, and combinations thereof. Non-limitingexamples of metals include titanium and stainless steel. Non-limitingexamples of polymers include polyether ether ketone (PEEK),ultra-high-molecular-weight polyethylene (UHMPE), polyoxymethylene (POM)such as Delrin® available from DuPont of Wilmington, Del., Radel®polyphenylsulfone (Radel PPSU) available from Solvay S.A. of Ixelles,Brussels, Belgium, and carbon fiber reinforced polymers (CRFP) such asPEEK reinforced with carbon fibers. In an exemplary embodiment, theretractor can be formed from one or more radiolucent polymers, e.g.,PEEK, which can allow the retractor to be substantially invisible in aradiographic image, e.g., an x-ray. A radiolucent retractor canfacilitate inspection of a patient's anatomy and other objects in aradiographic image, e.g., without the retractor appearing dark on theimage and hindering visualization of objects located behind the darkretractor and/or without reflections from blades of the retractorcreating a bright spot within a working channel defined by the retractorblades and hindering visualization of objects located within or beyond adistal end of the working channel.

Any portion of the retractor can be formed from a radiolucentmaterial(s). At least a portion of the retractor within a zone ofvisualization can be formed from a radiolucent material(s), e.g.,retractor blades formed from a radiolucent material(s) so as to make theretractor blades substantially invisible in a radiographic image andhelp prevent bright radioimage glare within a working channel defined bythe blades. In an exemplary embodiment, the entire retractor can beformed from a radiolucent material(s) so as to make the entire retractorsubstantially invisible in a radiographic image. A retractor beingentirely formed from a radiolucent material(s) also allows the retractorto be 100% disposable. While it is desirable to have retractors formedfrom a radiolucent material(s), the use of such materials with surgicalretractors can be difficult due to the use of numerous parts and movingparts. The retractors disclosed herein are particularly advantageous asthey utilize a relatively small number of moving parts, thus allowingall or least a substantial portion thereof to be formed while allowingintegrity of the device to be maintained. FIG. 1 shows an example of anx-ray of a spine with a retractor that is formed entirely from aradiolucent material(s) and that is retracting tissue adjacent thespine. The retractor of FIG. 1 is substantially invisible in the x-ray.In contrast, FIG. 2 (prior art) shows an example of an x-ray of a spinewith a retractor that is not formed from radiolucent material(s)retracting tissue adjacent the spine. The retractor of FIG. 2 is plainlyvisible as a dark object in the x-ray.

FIGS. 3-10 illustrate an exemplary embodiment of a retractor 10configured to retractor tissue. As shown, the retractor 10 can include abase 12, an actuator 14, and a plurality of retractor blades 16 a, 16 b,16 c, 16 d, 16 e, 16 f. Although the retractor 10 in this illustratedembodiment includes six blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f, theretractor can include any number of blades, e.g., two, three, four,five, seven, etc.

The retractor 10 can be configured to be movable between a closedposition, shown in FIGS. 3-6, and an open position, shown in FIGS. 7-10.As discussed further below, the actuator 14 can be configured to movethe retractor 10 between the open and closed positions. Generally, inthe closed position, the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f canbe in a collapsed position in which they are at a first end of theirfull range of movement and are at a closest distance to one another. Inthis position, the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f can definea working channel 18 having a diameter 18D at its smallest size.Generally, in the open position, the retractor 10 can be in an expandedposition in which the working channel 18 has a greater diameter 18D thanwhen the retractor 10 is in the closed position. When the retractor 10is in the open or expanded position, the blades 16 a, 16 b, 16 c, 16 d,16 e, 16 f can be fully open or partially open. In a fully openposition, as shown in FIGS. 9 and 10, the blades 16 a, 16 b, 16 c, 16 d,16 e, 16 f are at a second end of their full range of movement in whichthey are at farther distance apart from one another and thereby definethe diameter 18D of the working channel 18 at its greatest size. In apartially open position, as shown in FIGS. 7 and 8, the blades 16 a, 16b, 16 c, 16 d, 16 e, 16 f are at an intermediate position between thefirst and second ends of their full range of movement. Although FIGS. 7and 8 illustrate the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f in aparticular intermediate position, the blades 16 a, 16 b, 16 c, 16 d, 16e, 16 f can be positioned at any selected intermediate position betweenthe closed and fully open positions. The distance between the blades 16a, 16 b, 16 c, 16 d, 16 e, 16 f can therefore be increased or decreasedto any desired extent, thereby allowing the retractor 10 to adjust to analmost infinite number of positions, which can allow the retractor 10 tobe used with a variety of differently sized patients, with a variety ofdifferently sized tissue, and with a variety of differently sizedinstruments inserted through the working channel 18.

The base 12, which is illustrated as a standalone element in FIG. 11,can have a variety of sizes, shapes, and configurations. The base 12 caninclude a track 20 formed therein that can be configured to seat theactuator 14. The actuator 14 seated in the track 20 can be configured tomove relative to the base 12, as discussed further below. As shown, thetrack 20 can be recessed within the base 12 to allow the actuator 14 tosit flush or sub-flush within the base 12, which can lower a profile ofthe retractor 10 for ease of packaging and ease of use. In theillustrated embodiment, as shown in FIGS. 3-10, a user-manipulatableportion of the actuator 14 can extend outside of the base 12 tofacilitate movement thereof, as also discussed further below. Also, thetrack 20 can be circular, which can facilitate rotation of the actuator14 within the track 20 relative to the base 12.

A sidewall 22 of the base 12 can help define the track 20 along with atop or proximal-facing surface 12 s of the base 12. As discussed furtherbelow, the proximal-facing surface 12 s of the base 12 is hidden by theactuator 14 seated within the track 20. The sidewall 22 can include arail configured to slidably engage a channel 30 formed in the actuator14, thereby helping to securely retain the actuator 14 within therecessed track 20. The rail can thus be configured to facilitate smoothand stable movement of the actuator 14 relative to the base 12. The railcan have a variety of configurations and can be integrally formed withthe base 12, or it can be one or more separate elements coupled thereto.In one embodiment, the sidewall 22 can have a continuous rail, e.g., aring, extending radially inward from an interior surface of the sidewall22. In another embodiment, the sidewall 22 can have a non-continuousrail, e.g., a series of aligned rails, extending radially inward from aninterior surface of the sidewall 22. In the illustrated embodiment, asshown in FIGS. 3, 4, and 11, the sidewall 22 includes a rail in the formof a plurality of rail pins 24 a, 26 a, 28 a mated to the sidewall 22via a plurality of interior holes 24 b formed in an interior surface ofthe sidewall 22 and a plurality of exterior holes 24 c, 24 d, 26 c, 26d, 28 c, 28 d formed in an exterior surface of the sidewall 22. Only oneinterior hole 24 b is visible in FIG. 11; the other two interior holes,corresponding respectively to the exterior holes 26 c, 26 d, 28 c, 28 d,are obscured in FIG. 11. The exterior holes 24 c, 24 d, 26 c, 26 d, 28c, 28 d can each be configured to seat an end of one of the rail pins 24a, 26 a, 28 a, e.g., exterior holes 24 c, 24 d seating rail pin 24 a,and the interior holes 24 b, 26 b, 28 b can each be configured to seat amid-portion of one of the rail pins 24 a, 26 a, 28 a, e.g., interiorhole 24 b seating rail pin 24 a. The rail pins 24 a, 26 a, 28 a can besecured within the various holes in a variety of ways, such as byinterference fit, snap fit, adhesive, etc. In the illustratedembodiment, the base 12 includes a rail and the actuator 14 includes achannel, but the base 12 can include a channel and the actuator caninclude a rail.

The base 12 can also be configured to seat each of the blades 16 a, 16b, 16 c, 16 d, 16 e, 16 f, such as by including a plurality of recesses30 a, 30 b, 30 c, 30 d, 30 e, 30 f each configured to seat one of theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f. In the illustratedembodiment, the recesses 30 a, 30 b, 30 c, 30 d, 30 e, 30 f can beformed in the proximal-facing surface 12 s of the base 12. In this way,as illustrated in FIGS. 6, 8, and 10, the blades 16 a, 16 b, 16 c, 16 d,16 e, 16 f, e.g., proximal ends of the blades 16 a, 16 b, 16 c, 16 d, 16e, 16 f, can each be seated in one of the recesses 30 a, 30 b, 30 c, 30d, 30 e, 30 f and can be sandwiched between the actuator 14, e.g., adistal-facing surface 14 s of the actuator 14, and the base 12, e.g.,the proximal-facing surface 12 s of the base 12.

The sidewall 22 that defines the perimeter of the base 12 can include aplurality of windows 32 a, 32 b, 32 c, 32 d, 32 d, 32 e, 32 f formedtherethrough, as shown in FIGS. 4 and 11. Each of the plurality ofwindows 32 a, 32 b, 32 c, 32 d, 32 d, 32 e, 32 f can be configured toallow a different one of the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 fto advance therethrough when the actuator 14 is actuated to move theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f relative to the base 12, asdiscussed further below. A number of the windows 32 a, 32 b, 32 c, 32 d,32 d, 32 e, 32 f, six in the illustrated embodiment, can therefore equala number of the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f. The windows32 a, 32 b, 32 c, 32 d, 32 d, 32 e, 32 f can each have a size and shapecomplementary to a cross-sectional shape of a portion of the blades 16a, 16 b, 16 c, 16 d, 16 e, 16 f that can move therethrough, as discussedfurther below.

The base 12 can include a handle configured to be gripped by hand and/orbe mounted to a stable object, e.g., a table, a wall, etc. The sidewall22 or other base portion defining the track 20 can serve as a retractorhandle, or, as in the illustrated embodiment, the retractor 10 caninclude a handle 34 extending radially outward from the sidewall 22. Thehandle 34 in the illustrated embodiment is in the form of an arcuateflange extending radially outward from the sidewall 22, but the handlecan extend in any one or more directions, e.g., extend proximally, beL-shaped so as to extend radially and proximally, etc. The handle 34can, as in the embodiment shown in FIG. 4, curve in a distal direction,which can help provide easier access to the proximally-accessibleactuator 14. In another embodiment, the handle can be co-planar with thesidewall 22. The handle 34 can include one or more gripping features,e.g., a textured surface, one or more finger depressions 36, etc.configured to facilitate hand manipulation of the retractor 10. Thehandle 34 can include one or more mounting mechanisms configured tofacilitate mounting of the retractor 10 to a stable object to allowhands-free use of the retractor 10 during a surgical procedure. In theillustrated embodiment, as shown in FIGS. 3-5 and 11, the handle 34includes a notch 37 configured to be snap fit onto a complementarymounting mechanism (not shown), but the mounting mechanism can have avariety of other configurations, e.g., threads, clamp, etc.

The actuator 14, shown in FIGS. 3-10 and as a standalone element inFIGS. 12-14, can also have a variety of sizes, shapes, andconfigurations. The actuator 14 can be configured to be seated in thetrack 20 of the base 12 and to be operatively connected to the blades 16a, 16 b, 16 c, 16 d, 16 e, 16 f to cause movement thereof relative tothe base 12 when the actuator 14 is actuated, e.g., rotated within thetrack 20, relative to the base 12. The actuator 14 can have a size andshape complementary to the track 20 formed in the base 12 in which theactuator 14 can be seated. Thus, as in the illustrated embodiment, theactuator 14 can include a ring having a circular shape complementary tothe circular track 20 and having a central void. In other embodiments,the actuator can be configured as a circular disc having a centralperforation or central overlapping flaps aligned with the workingchannel 18 such that an instrument can be inserted through theperforation or flaps and then pass into the working channel 18.

As mentioned above, and as shown in FIGS. 12 and 13, the actuator 14 caninclude the channel 30 formed therein to engage the rail pins 24 a, 26a, 28 a seated in the base 12. The channel 30 can, as in the illustratedembodiment, extend around a full outer perimeter of the actuator 14 toallow rotation of the actuator 14.

As also mentioned above, the actuator 14 can be configured to be movablerelative to the base 12 to cause the blades 16 a, 16 b, 16 c, 16 d, 16e, 16 f to expand and collapse relative to the base 12 so as to increaseand decrease the diameter 18D of the working channel 18. Generally, theactuator 14 can be actuated, e.g., rotated, to cause the actuator 14 tomove, e.g., rotate, relative to the base 12 and thereby cause the blades16 a, 16 b, 16 c, 16 d, 16 e, 16 f to move relative to the base 12. Whenthe actuator 14 is rotated relative to the base 14, the rail pins 24 a,26 a, 28 a can slide within the channel 30.

Instead of the rail/channel system which facilitates rotation of theactuator 14 relative to the base 12 in the illustrated embodiment, aretractor can include a variety of other mechanisms configured tofacilitate rotation of the actuator relative to the base. Fornon-limiting example, a retractor can include a ratchet/pawl system. Thebase can include a pawl, and the actuator can include a circular ratchetincluding a plurality of teeth configured to engage the pawl. When theactuator is rotated relative to the base, the pawl can disengage fromone of the teeth and engage another one of the teeth when the actuatorceases rotating. The ratchet/pawl system can include a stop mechanism,e.g., a stop surface formed on the ratchet against which the pawl abuts,configured to stop rotation of the actuator beyond a certain point so asto prevent the actuator from rotating so far that one or more of theblades become disengaged from the base. The ratchet can include one orboth of a stop mechanism to stop rotation in one direction, e.g.,clockwise, and another stop mechanism to stop rotation in the otherdirection, e.g., counterclockwise. Alternatively, the actuator caninclude a pawl, and the base can include a ratchet.

The actuator 14 can include one or more gripping features configured tofacilitate manual movement of the actuator 14. In the illustratedembodiment, the actuator 12 includes a plurality of finger grips 38,e.g., proximally raised protrusions contoured on opposed sides thereofto receive fingertips, to facilitate manual rotation of the actuator 14relative to the base 12. Although the actuator 14 in the illustratedembodiment includes five finger grips 38, the actuator 38 can includeany number of finger grips. Also, instead of or in addition to thefinger grips 38, the actuator 14 can include other gripping featuressuch as a textured surface, one or more finger loops, one or more fingerdepressions, a slide lever, a knob, etc.

As will be appreciated by a person skilled in the art, the actuator 14can be manually actuated by hand and/or by using one or more tools. Fornon-limiting example, a tool can be pushed against one or more of thefinger grips 38 to push the actuator 14 and cause rotation thereof. Foranother non-limiting example, the actuator can include one or more toolopenings or loops configured to receive an end of a tool therein suchthat moving the tool can push the actuator 14 and cause rotationthereof.

As mentioned above, the actuator 14 can be operatively connected to theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f to cause movement thereof whenthe actuator 14 is rotated relative to the base 12. The actuator 14 canbe operatively connected to the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16f in a variety of ways. As in the illustrated embodiment, the actuator14 can include a scroll gear or chuck, referred to herein as a “scrollgear,” configured to operatively connect to the blades 16 a, 16 b, 16 c,16 d, 16 e, 16 f via interlocking features formed on the actuator 14 andon the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f. The scroll gear canhave a variety of configurations and can be self-locking, as in theillustrated embodiment and as discussed further below. The distal-facingsurface 14 s of the actuator 14 can include a thread 40 formed thereonin the form of a continuous spiral thread, as shown in FIGS. 13 and 14,which can serve as the interlocking feature of the actuator 14configured to engage the corresponding interlocking feature of theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f. The distal-facing surface 14s of the actuator 14 can be inclined or curved distally inward, as shownin FIGS. 6, 8, 10, and 12, which can help the actuator 14 self-lock andhelp the actuator 14 maintain operative connection with the blades 16 a,16 b, 16 c, 16 d, 16 e, 16 f, as discussed further below. In otherwords, the distal-facing surface 14 s of the actuator 14 can be slopedin a proximal-to-distal direction from an outer-most region to aninner-most region of the actuator's central opening. Correspondingly,the proximal-facing surface 12 s of the base 12 s can be inclined orcurved distally inward, e.g., be sloped in a proximal-to-distaldirection from an outer-most region to an inner-most region of thebase's central opening.

The blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f can also have a variety ofsizes, shapes, and configurations. In an exemplary embodiment, each ofthe blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f can be substantially thesame as one another, as in the illustrated embodiment. A person skilledin the art will appreciate that the blades 16 a, 16 b, 16 c, 16 d, 16 e,16 f may be substantially identical but not be precisely identical toone another due to one or more factors such as manufacturing tolerances,color coding and/or other coding such as printed numerical coding forease of identification, etc. For ease of illustration and discussion, afirst one of the blades 16 a, illustrated in FIGS. 6, 8, 10, 15A, and15B, is discussed as a representative one of the blades 16 a, 16 b, 16c, 16 d, 16 e, 16 f. Although the retractor 10 in this illustratedembodiment includes six blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f, aretractor can have any number of blades.

As best shown in FIGS. 15A and 15B, the first blade 16 a can include aproximal portion 17 p configured to engage the actuator 14 and the base12 and a distal portion 17 d configured to extend from the base 12 andto contact and retract tissue. The distal portion 17 d can extend at anon-zero angle α, e.g., greater than 0 degrees and less than 180degrees, relative to the proximal portion 17 p. The angle α can vary,but in an exemplary embodiment, the angle α can be about 90 degrees, asin the illustrated embodiment, such that the distal portion 17 d of theblade 16 a extends substantially perpendicular to a plane P, shown inFIG. 4, in which the actuator 14 rotates. In this way, the workingchannel 18 defined by the distal portions of the blades 16 a, 16 b, 16c, 16 d, 16 e, 16 f, e.g., a longitudinal axis 18A of the workingchannel 18, shown in FIG. 4, can extend substantially perpendicular tothe plane P in which the actuator 14 rotates, which can help facilitateaccess to and simultaneous handling of the actuator 14 and an instrumentinserted through the working channel 18. A person skilled in the artwill appreciate that the angle α of the distal portion 17 d of theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f relative to the longitudinalaxis 18A of the working channel 18 can vary as the blades 16 a, 16 b, 16c, 16 d, 16 e, 16 f move between the collapsed and expanded positions.

The distal portion 17 d of the first blade 16 a can have a variety ofsizes, shapes, and configurations. In this illustrated embodiment, thedistal portion 17 d has a fixed longitudinal length, but as will beappreciated by a person skilled in the art, the distal portion 17 d canhave a variable longitudinal length, such as by being configured as atelescoping blade. Additionally, a retractor can include blades that areall telescoping, or a retractor can include some telescoping blades andsome non-telescoping blades. In some embodiments, a retractor can beconfigured to have one or more removable blade extenders mates to one ormore blades of the retractor so as to extend the longitudinal lengths ofthe one or more blades.

The distal portion 17 d can have a curved profile such that the blade 16a is curved about a longitudinal axis of the distal portion 17 d of theblade 16 a, as in this illustrated embodiment in which the distalportion 17 d has an arcuate cross-sectional shape. Collectively, thecurved profiles of the distal portions of the blades 16 a, 16 b, 16 c,16 d, 16 e, 16 f can define the working channel 18, which in thisembodiment has a closed cylindrical shape, e.g., a circularcross-sectional shape, when the retractor 10 is in the closed position.In other embodiments, the distal portions of the blades 16 a, 16 b, 16c, 16 d, 16 e, 16 f can have profiles defining a non-cylindrical workingchannel when the retractor is in a closed position, such as a workingchannel having an elliptical cross-sectional shape, a square orrectangular cross-sectional shape, an irregular cross-sectional shape, atriangular cross-sectional shape, etc.

The distal portions of the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f canbe configured to nest or overlap with one another, at least when theretractor 10 is closed and the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 fare in the collapsed position. By being nested or overlapped, the blades16 a, 16 b, 16 c, 16 d, 16 e, 16 f can have a smaller diameter thannon-nested or non-overlapped blades. In other words, the blades 16 a, 16b, 16 c, 16 d, 16 e, 16 f defining a relatively small working channeldiameter 18D can be inserted into a patient's body through a relativelysmall opening and can be configured to radially expand to achieve a muchlarger working channel diameter 18D. As shown in the illustratedembodiment in FIGS. 3-6 and 16, when the retractor 10 is in the closedposition, the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f can be nested oroverlapped with a first number of the blades 16 a, 16 c, 16 e definingan outer surface of the working channel 18, e.g., defining an exteriorof the working channel's shape, and a remaining number of the blades 16b, 16 d, 16 f defining an inner surface of the working channel 18, e.g.,defining an interior of the working channel's shape. The blades 16 a, 16b, 16 c, 16 d, 16 e, 16 f can therefore nest or overlap such that thefirst number of blades 16 a, 16 c, 16 e can be completely obscured fromthe interior of the working channel's shape, and the remaining number ofthe blades 16 b, 16 d, 16 f can be completely obscured from the exteriorof the working channel's shape. Each of the first number of blades 16 a,16 c, 16 e, e.g., outer blades, can have their longitudinal edges abutone another so as to define a first closed cylindrical shape, as shownin FIG. 16. Similarly, each of the remaining number of blades 16 b, 16d, 16 f, e.g., inner blades, can have their longitudinal edges abut oneanother so as to define a second closed cylindrical shape. Havingobscured blades can help the retractor 10 be smoothly inserted into apatient and can help prevent any instruments inserted through theworking channel 18 when the retractor 10 is closed from passing outsidethe working channel 18 before exiting through an open distal endthereof, thereby helping to prevent accidental tissue damage. Suchobscuring can also facilitate effective tissue retraction because whenthe retractor 10 is moved from the closed position to the open position,e.g., moved from the position shown in FIG. 16 to the position shown inFIG. 17, the first number of the blades 16 a, 16 c, 16 e can contact andretract tissue before the remaining number of blades 16 b, 16 d, 16 fcontact and retract the tissue. The remaining number of blades 16 b, 16d, 16 f can therefore be configured to “catch” and retract tissue thatslips between the first number of blades 16 a, 16 c, 16 e as the firstnumber of the blades 16 a, 16 c, 16 e retract the tissue.

When the retractor 10 includes an even number of blades 16 a, 16 b, 16c, 16 d, 16 e, 16 f, as in the illustrated embodiment, the first numberof blades can equal the remaining number of blades such that half theblades define an exterior shape of the working channel and half theblades define an interior shape of the working channel. Thus, when theblades are in the collapsed position, half a number, e.g., three, of theblades can define the size of the working channel rather than all, e.g.,six, of the blades defining the working channel's size. When a retractorhas an odd number of blades, the first number of blades or the remainingnumber of blades may be larger than the other, e.g., two exterior bladesthree interior blades, three exterior blades and four interior blades,etc.

The proximal portion 17 p of the first blade 16 a can also have avariety of sizes, shapes, and configurations. The proximal portion 17 pof the first blade 16 a can be configured to be non-removable from thebase 12, as in the illustrated embodiment in which all of the blades 16a, 16 b, 16 c, 16 d, 16 e, 16 f are non-removably coupled to the base12. Alternatively, any one of more of the blades can be configured toremovably and replaceably couple to the base in any of a variety ofways, as will be appreciated by a person skilled in the art. Fornon-limiting example, an end portion of a blade can be configured as adepressible button such that pressing the button down can allow theblade to slide out of or into the blade's associated window formed inthe base of the retractor. For another non-limiting example, a proximalportion of a blade can be configured to be non-removable from a base,similar to the proximal portion 17 p in the illustrated embodiment, andcan be configured to have a distal portion of the blade removably andreplaceably coupled thereto, e.g., by snap fit. By including one or moreblades with removable and replaceable distal portions, optimal bladesizes can be selected for use in accordance with a particular procedureperformed on a particular patient.

The proximal portion 17 p of the first blade 16 a can curve or bendslightly upward, as shown in FIG. 15B, along a longitudinal length L1thereof. As shown, a first end 19 a of the proximal portion 17 p can beattached to the distal portion 17 d, and the proximal portion 17 p cancurve or bend upwards toward a second, opposite end 19 b of the proximalportion 17 p, e.g., be sloped in a radially outward direction from thefirst end 19 a to the second end 19 b. This curve or bend can facilitatemovement of the blade 16 a relative to the base 12, as discussed furtherbelow. The proximal portion 17 p can have a linear or non-arcuatecross-sectional shape. In other words, a width W1 of the proximalportion, shown in FIG. 15A, can have a substantially flat profile, asopposed to the curved profile of the distal portion 17 d discussedabove.

The proximal portion 17 p of the first blade 16 a can include aplurality of ridges or teeth 42 a, 42 b, 42 c, 42 d, referred to hereinas “teeth,” formed thereon. The teeth 42 a, 42 b, 42 c, 42 d can extendacross the width W1 of the proximal portion 17 p on a proximal surfaceof the proximal portion 17 p. The teeth 42 a, 42 b, 42 c, 42 d can bealigned linearly and radially such that a first one of the teeth 42 a isan innermost one of the teeth 42 a, e.g., closest to the first end 19 aof the proximal portion 17 p attached to the distal portion 17 d, with aremainder of the teeth 42 b, 42 c, 42 d being spaced radially outwardtoward the second end 19 b of the proximal portion 17 p. Although thefirst blade 16 a includes four teeth, the retractor blades can eachinclude any number of teeth. The first blade 16 a can also include firstand second end stops 44 a, 44 b. The first and second end stops 44 a, 44b can be configured similar to the teeth 42 a, 42 b, 42 c, 42 d and canbe positioned on either radial end of the teeth 42 a, 42 b, 42 c, 42 d,as shown in FIG. 15A, such that the first end stop 44 a can bepositioned radially inward of the first tooth 42 a, and the second endstop 44 b can be positioned radially outward of a last one 44 d of theteeth. In some embodiments, the second end stop 44 b can be configuredas a depressible button such that, as discussed above, the depressiblebutton can be depressed to selectively allow removal of the blade fromand attachment of the blade to the base 12. The other blades 16 b, 16 c,16 d, 16 e, 16 f can be identical to the first blade 16 a, as mentionedabove, and thus can each also include teeth and end stops similar to thefirst blade 16 a.

The teeth 42 a, 42 b, 42 c, 42 d and the end stops 44 a, 44 b canprotrude proximally from a surface of the first blade 16 a so as to beconfigured to engage the thread 40 of the actuator 14, which can bepositioned proximal to the blade 16 a, as shown in FIGS. 6, 8, 10, 16,and 17. The thread 40 of the actuator 14 can therefore be configured toengage the plurality of teeth and the plurality of end stops formed oneach of the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f. Similarly, theplurality of teeth and the plurality of end stops formed on each of theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f can define a channel or groovefor the thread 40 to slidably move within when the actuator 14 rotatesrelative to the base 12. For ease of illustration and discussion, thefirst blade 16 a having the plurality of teeth 42 a, 42 b, 42 c, 42 dformed thereon, as shown in FIGS. 6, 8, 10, 15A, and 15B, is discussedwith reference to the thread 40 and movement of the actuator 14 relativeto the base 12.

The thread 40 of the actuator 14 can be configured to be slidablebetween the teeth 42 a, 42 b, 42 c, 42 d, e.g., to thread between theteeth 42, as the actuator 14 is rotated relative to the base 12. In thisway, the thread 40 can cause the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16f to move radially inward or radially outward relative to the base 12,e.g., laterally relative to the base 12 and transverse to thelongitudinal axis 18A of the working channel 18, depending on adirection of the actuator's rotation.

In another embodiment, a retractor can be configured to be positioned ina stable configuration which can be used during radially outward andradially inward motion of the retractor's blades relative to theretractor's base. Such a retractor and its various elements, e.g.,blades, base, etc., can be generally configured and used similar toother like-named elements discussed herein. The retractor can include astable blade, e.g., one of the blades removably and replaceably mated tothe base, configured to be mounted to a stable object, e.g., a table,one or more a rigid arms, a wall, etc., without the base or any of theother blades being mounted to the stable object. In the stableconfiguration, the stable blade can be so mounted so as to allowmovement of the blades with the stable blade as a stationary reference.The stable blade can include a mounting mechanism in a proximal portionthereof, e.g., in a portion of the blade configured to mate to the base.The mounting mechanism can have a variety of configurations, e.g., anotch configured to be snap fit to a complementary mounting mechanism,threads, clamp, etc. In this way, in use, the stable blade can be theonly element of retractor that is stabilized to the patient. Duringrotation of the retractor's actuator, the blades can move relative toeach other, however the base and consequently the working channel, e.g.,a longitudinal axis of the working channel, can migrate away from ortowards the stable blade. In other words, the stable blade can beconfigured to remain stationary relative to the patient and to thestable object to which the stable blade is mounted.

Rotating the actuator 14 in a first direction, e.g., clockwise, relativeto the base 12 can cause the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 fto move radially outward relative to the base 12 as the thread 40 slidesbetween different ones of the teeth 42 a, 42 b, 42 c, 42 d. Because theactuator 14 is held in place within the track 20 as the actuator 14rotates, e.g., the actuator 14 does not move radially relative to thebase 12, the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f can move throughthe thread 40. The inclined or curved bottom profile of the actuator 14can help maintain contact between the thread 40 and the blades 16 a, 16b, 16 c, 16 d, 16 e, 16 f as the actuator 14 rotates relative to thebase 12 and the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f move relativeto the base 12. This contact can help slide the blades 16 a, 16 b, 16 c,16 d, 16 e, 16 f radially outward along the inclined or curvedproximal-facing surface 12 s of the base 12 s and through theirrespective 32 a, 32 b, 32 c, 32 d, 32 e, 32 f formed in the base'ssidewall 22. In other words, rotating the actuator 14 can cause theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f to pivot radially outward.Correspondingly, rotating the actuator 14 in a second, oppositedirection, e.g., counterclockwise, relative to the base 12 can cause theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f to move radially inwardrelative to the base 12, e.g., pivot radially inward.

The pivoting of the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f radiallyoutward can cause the diameter 18D of the working channel 18 to differbetween a proximal end 18 p and a distal end 18 i thereof, as shown inFIGS. 8 and 10, when the retractor 10 is in the open position, e.g.,when the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f are in the expandedposition. In particular, a diameter 18D1 of the working channel 18 atthe proximal end 18 p thereof can be less than a diameter 18D2 of theworking channel 18 at the distal end 18 i thereof. The working channel18 can thereof have a distally-tapering cone or pyramid shape when theretractor 10 is in the open position. In contrast, when the retractor 10is in the closed position, e.g., when the blades 16 a, 16 b, 16 c, 16 d,16 e, 16 f are in the collapsed position, as shown in FIG. 6, thediameters 18D1, 18D2 of the working channel 18 at the proximal anddistal ends 18 p,18 i and can be the same and can be constant along alongitudinal length thereof so as to define a cylindrically shapedworking channel.

As shown in FIGS. 6, 8, and 10 of the illustrated embodiment, when theretractor 10 is the closed position with the blades 16 a, 16 b, 16 c, 16d, 16 e, 16 f in the collapsed position, rotating the actuator 14 in thefirst direction can cause the teeth of the blades 16 a, 16 b, 16 c, 16d, 16 e, 16 f to move through the thread 40 of the actuator 14, therebyadvancing each of the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f radiallyoutward through their respective windows 32 a, 32 b, 32 c, 32 d, 32 e,32 f formed in the base's sidewall 22, and moving the retractor 10 tothe open position with the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f inthe expanded position. In other words, when the retractor 10 is in theclosed position, as shown in FIGS. 3-6, the thread 40 can be positionedin spaces defined by outermost ones of the teeth 42 c, 42 d and thesecond end stop 44 b, e.g., positioned in two spaces, and the blades 16a, 16 b, 16 c, 16 d, 16 e, 16 f can be substantially contained within aperimeter or circumference of the base 12 as defined by the base'ssidewall 22, e.g., the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f notbeing positioned radially outward of the windows 32 a, 32 b, 32 c, 32 d,32 e, 32 f. From when the retractor 10 is in the closed position, theactuator 14 can be rotated to move the blades 16 a, 16 b, 16 c, 16 d, 16e, 16 f radially outward through the windows 32 a, 32 b, 32 c, 32 d, 32e, 32 f such that the thread 40 can eventually be positioned betweenspaces defined by innermost ones of the teeth 42 a, 42 b and the firstend stop 44 a, e.g., positioned in two spaces different from when theretractor 10 is in the closed position, when the retractor 10 is fullyopen, as shown in FIG. 10. Although, as well be appreciated by a personskilled in the art, the actuator 14 need not be rotated to fully openthe retractor 10 but instead be rotated to move the retractor 10 to apartially open position, such as the partially open positionedillustrated in FIGS. 7 and 8. Similarly, rotating the actuator 14 in thesecond direction can cause the reverse to occur, thereby advancing eachof the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f radially inward throughtheir respective openings 32 a, 32 b, 32 c, 32 d, 32 e, 32 f formed inthe base sidewall 22, and moving the retractor 10 toward the closedposition.

The blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f can be prevented frommoving beyond a certain expanded or collapsed point by the thread 40running out of space to move along the proximal portions of the blades16 a, 16 b, 16 c, 16 d, 16 e, 16 f on either end of the actuator'sclockwise or counterclockwise rotation. In other words, the end stops ofthe blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f, e.g., the end stops 44 a,44 b of the first blade 16 a, can be configured to define thresholdpositions of the actuator 14 relative to the base 12 to prevent furtherrotation of the actuator 14 relative to the base 12 when the thread 40abuts either of the end stops 44 a, 44 b, e.g., when the retractor 10 isfully open as shown in FIG. 10 or closed as shown in FIG. 6. The teethand end stops of the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f cantherefore define the blades' range of movement.

The actuator 14 can be configured to be self-locking, as mentionedabove. In this way, the actuator 14 can be controllably rotated to anyselected position relative to the base 12 to freely move the blades 16a, 16 b, 16 c, 16 d, 16 e, 16 f relative to the base 12 and hold theblades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f in any selected positionrelative to the base 12. When the actuator 14 is not rotating, theactuator 14, e.g., a curvature of the distal-facing surface 14 and apitch of the thread 40 which can approximate the curvature, can beconfigured to help hold the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f inposition relative to the base 12, thereby preventing the blades 16 a, 16b, 16 c, 16 d, 16 e, 16 f from slipping relative to any tissue they areretracting and/or to any instrument inserted through the working channel18. The actuator 14 can therefore be configured to counteract radiallyoutward forces applied by the blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 fand thereby prevent the teeth of the blades 16 a, 16 b, 16 c, 16 d, 16e, 16 f from sliding relative to the thread 40 when the actuator 14 isnot being manually rotated. As mentioned above, the curved profile ofthe distal-facing surface 14 s of the actuator 14 and the curved profileof the proximal-facing surface 12 s of the base 12 in cooperation withthe engagement between the thread 40 of the actuator 14 and the teeth ofthe blades 16 a, 16 b, 16 c, 16 d, 16 e, 16 f can help hold the blades16 a, 16 b, 16 c, 16 d, 16 e, 16 f in position relative to the base 12.A ratio of an average diameter of the thread 40 to the pitch of thethread 40, e.g., a distance between innermost teeth 42 a, 42 b, canallow the self-locking of the actuator 14. In an exemplary embodiment,the ratio can be in a range of about 0.03 to 0.2, e.g., about 0.08(e.g., a pitch of about 8 mm and an average thread diameter of about 100mm). The smaller the ratio, the more effectively the actuator 14 canself-lock. A co-efficient of friction between the blades 16 a, 16 b, 16c, 16 d, 16 e, 16 f and the actuator 14 can also help hold the blades 16a, 16 b, 16 c, 16 d, 16 e, 16 f in position relative to the base 12.

In some embodiments, the retractor 10 can be inserted over an obturatorduring insertion of the retractor to the depth of the surgical site ornear the depth of the surgical site to be formed. FIGS. 18-20 illustrateone embodiment of such a method used to retract tissue near the spine ofa human. Soft tissue and some bone mass has been omitted from thefigures for clarity. A person skilled in the art will appreciate thatwhile use of the retractor 10 is shown and described with reference toFIGS. 18-20 as retracting tissue adjacent a spine, any retractordisclosed herein can be used similarly, and the methods and devicesdisclosed herein can be used to retract tissue in a variety of medicalprocedures at various places around a patient's body.

FIG. 18 illustrates an obturator 100 after it has been inserted into anincision and directed to a surgical site 102, e.g., next to a spinalcolumn. Optionally, the obturator 100 can be directed along a guide wire(not shown) which has previously been tethered to the surgical site 102.Once the obturator 100 is in position at the surgical site 102, theretractor 10 can be advanced over the obturator 100, e.g., with theobturator passing through the working channel 18, to the surgical site102. The retractor 10 in the closed position can be advanced alone overthe obturator 100, as shown in FIG. 19. Alternatively, as will beappreciated by a person skilled in the art, the retractor 10 can becoupled to an introducer device (not shown) configured to advance theretractor 10 along the obturator 100. Whether advanced using anintroducer device or not, the retractor 10 can be advanced distally tothe surgical site 102 by pushing the retractor 10 down the length ofobturator 100 to the surgical site 102, as shown in FIG. 19. Once theretractor 10 is at the surgical site 102, the obturator 100 can beremoved from the incision, leaving the retractor 10 at the surgical site102. Instead of using the obturator 100 to guide the retractor 10 to thesurgical site 102, as will be appreciated by a person skilled in the artthe retractor 10 can be advanced to the surgical site 102 in a number ofother ways, e.g., using a guide wire, using an introducer device, handinsertion, etc. Optionally, at any point during the procedure, theretractor 10 can be attached to a surgical retractor positioningmechanism, e.g. a table, one or more a rigid arms, a wall, etc., torigidly secure the retractor 10 at a fixed location relative to thesurgical site 102.

Once positioned at the surgical site 102, the retractor 10 can beactuated as discussed above to retract tissue at the surgical site 102.With the retractor 10 in the closed position or in the open position,one or more surgical instruments 104 can be inserted through the workingchannel 18 of the retractor 10, as shown in FIG. 20 with the retractor10 in the closed position, such that a distal end 104 d of theinstrument 104 extends through the working channel 18 to access bone,tissue, and/or other matter at the surgical site 102. Although a grasperwith jaws is illustrated as the instrument 104 in FIG. 20, a personskilled in the art will appreciate that any instrument can be insertedthrough the working channel 18.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of the particular pieces or parts ofthe device, e.g., the blades, can be selectively replaced or removed inany combination. Upon cleaning and/or replacement of particular parts,the device can be reassembled for subsequent use either at areconditioning facility, or by a surgical team immediately prior to asurgical procedure. Those skilled in the art will appreciate thatreconditioning of a device can utilize a variety of techniques fordisassembly, cleaning/replacement, and reassembly. Use of suchtechniques, and the resulting reconditioned device, are all within thescope of the present application.

Preferably, the invention described herein will be processed beforesurgery. First, a new or used instrument is obtained and if necessarycleaned. The instrument can then be sterilized. In one sterilizationtechnique, the instrument is placed in a closed and sealed container,such as a plastic or TYVEK bag. The container and instrument are thenplaced in a field of radiation that can penetrate the container, such asgamma radiation, x-rays, or high-energy electrons. The radiation killsbacteria on the instrument and in the container. The sterilizedinstrument can then be stored in the sterile container. The sealedcontainer keeps the instrument sterile until it is opened in the medicalfacility.

It is preferred that device is sterilized. This can be done by anynumber of ways known to those skilled in the art including beta or gammaradiation, ethylene oxide, steam, and a liquid bath (e.g., cold soak).

One skilled in the art will appreciate further features and advantagesof the invention based on the above-described embodiments. Accordingly,the invention is not to be limited by what has been particularly shownand described, except as indicated by the appended claims. Allpublications and references cited herein are expressly incorporatedherein by reference in their entirety.

What is claimed is:
 1. A surgical device, comprising: a base; aplurality of retractor blades having a proximal end coupled to the baseand a distal portion extending distally from the base, the blades beingconfigured to move radially relative one another between a collapsedposition and an expanded position in which the blades define a workingchannel for receiving an instrument therethrough and in which a diameterof the working channel is greater than the diameter of the workingchannel when the blades are in the collapsed position; and an actuatorcoupled to the base, the actuator being configured to rotate relative tothe base to cause the blades to move between the collapsed and expandedpositions.
 2. The device of claim 1, wherein the actuator isself-locking such that the actuator is configured to freely move theblades between the collapsed and expanded positions without requiringactuation of a release mechanism.
 3. The device of claim 1, wherein theactuator comprises a scroll gear.
 4. The device of claim 1, wherein theactuator is configured such that rotating the actuator in a firstdirection moves the blades to the collapsed position, and rotating theactuator in a second direction opposite to the first direction moves theblades to the expanded position.
 5. The device of claim 1, wherein theactuator is seated in the base and is operatively connected to theproximal ends of the blades.
 6. The device of claim 1, wherein theactuator is in the form of a ring disposed within a track formed in thebase.
 7. The device of claim 1, wherein when the blades are in thecollapsed position at least one of the blades has an inner surfacefacing an outer surface of at least another one of the blades such thatthe at least one of the blades and the at least another one of theblades overlap.
 8. The device of claim 1, wherein the base, the blades,and the actuator are formed from a radiolucent material.
 9. A surgicaldevice, comprising: a base; and a plurality of retractor bladesextending from the base, the plurality of retractor blades having acollapsed position and an expanded position, the plurality of retractorblades in the collapsed position overlapping one another such that theplurality of retractor blades define a single working channel having aclosed cylindrical shape, and the plurality of retractor blades in theexpanded position being spaced a distance apart from one another. 10.The device of claim 9, wherein, when the plurality of retractor bladesare in the collapsed position, at least one of the plurality ofretractor blades is positioned radially inward of at least another oneof the plurality of retractor blades.
 11. The device of claim 10,wherein, when the plurality of retractor blades are in the collapsedposition, the at least one of the plurality of retractor blades iscompletely obscured from the exterior of the closed cylindrical shape.12. The device of claim 9, further comprising an actuator coupled to thebase, the actuator being configured to rotate relative to the base tocause the plurality of retractor blades to move between the collapsedand expanded positions.
 13. The device of claim 12, wherein the actuatorincludes a self-locking scroll gear.
 14. A surgical device, comprising:a base; a plurality of retractor blades extending from the base andconfigured to retract tissue, each of the blades having a proximal endcoupled to the base, the blades being configured to move radially towardand away from one another; and a self-locking actuator coupled to thebase, the actuator being configured to move relative to the base tocause the blades to move radially toward and away from one another, andthe actuator being configured to self-lock the blades in any selectedposition relative to one another within a range of movement of theblades.
 15. The device of claim 14, wherein the actuator is configuredto self-lock the blades in any selected position relative to one anotherby moving the actuator relative to the base without actuation of a lockmechanism, and the blades are configured to unlock by moving theactuator relative to the base without actuation of a release mechanism.16. The device of claim 14, wherein the actuator is configured to rotaterelative to the base to cause the blades to move toward and away fromone another.
 17. The device of claim 14, wherein the actuator comprisesa scroll gear.
 18. A surgical method, comprising: inserting a retractorthrough an incision formed in tissue; and rotating an actuator of theretractor in a first direction relative to a base of the retractor tocause blades of the retractor that are coupled to the base to moveradially away from one another to expand the incision and to form aworking channel that provides access to a body cavity.
 19. The method ofclaim 18, wherein the actuator self-locks to lock the blades in a fixedposition relative to one another.
 20. The method of claim 18, whereinthe actuator is rotated relative to the base without actuating a releasemechanism.